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What Is A Firewall? Network Security Devices Explained

In this age of technology, cyber security has become a major concern, including issues like invasion of privacy, identity theft, and theft of financial information. In times like these, it’s imperative to understand the measures that must be taken to secure the use of everyday electronic devices. One essential tool providing essential protection is the firewall.

A firewall is a simple yet effective network security device to ensure the protection of privacy and sensitive data. Firewalls act as gatekeepers for your devices by checking the credentials of incoming data and deciding whether to permit or block access.

Firewalls can come off as a rather difficult thing to understand and work with, but the concept behind them is more simple and straightforward than you might think. A firewall’s job is exactly what it sounds like, to be a barrier between your device and external networks. Let’s take a closer look at firewalls and how they work.

What Is a Firewall and How Does It Work?

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A firewall acts as a gatekeeper. Any data that enters your device from an external source needs to have valid credentials in order to gain access to your device. A very basic and preliminary credential is an IP address that identifies the source of the data coming in.

Any data stream/traffic whose source cannot be validated is flagged as untrusted. It is restricted from accessing your devices to prevent loss or compromising of data through malware which hackers try to get you to install by exploiting issues with device operating systems.

A firewall includes both software and hardware, with the hardware firewall being less well known. The hardware firewall consists of routers (wired and wireless) that act as a checkpoint for network traffic between independent devices.

Hardware firewalls work by analyzing incoming traffic from a source (internet) and deciding whether to allow or block it from accessing your device by running a set of instructions coded within its software. 

A software firewall is essentially software built to monitor and control the flow of network traffic between different devices and independently between a device and the internet. 

In most cases, one firewall can get the job done, however it really depends on the scenario. For a personal computer, a single firewall should suffice but in case of a company that has an extensive network, it is recommended to have multiple layers of firewall. 

Types of Firewalls

There are a various types of firewalls currently available in the market. Each serves a different purpose — but all in the name of security. To act as the first line of defense against malicious content from the internet, a router (wired/wireless) is the safest bet; however, it is only a basic layer of security.

Moreover, the hardware firewall works best when it’s coupled with software firewalls. A few software firewalls are mentioned below:

Packet Filtering Firewalls

This form of firewall can be classified as the most basic form of security when it comes to local network protection. This firewall filters incoming network traffic for IP protocol, IP addresses (source of data), and port numbers that are only allowed access if they are able to validate the pre-set parameter of this firewall. 

A packet filtering firewall is like a local area network guard that does not provide protection against assaults from the internet. Other types of firewalls need to work in tandem with it to provide a more enhanced form of security. The other types are mentioned ahead. 

There are a few firewall pre-sets you can apply when it comes to packet filters:

Dynamic Packet Filters

This is a more diverse set of firewall, where filters can be changed to adapt to the type and instance of data flow. Here, port opening can be set to open at specific times. This form of firewall is far more sophisticated than the other forms of packet filters.

Static Packet Filters

These work more towards the point firewall with a set of rules that are followed throughout, as long as the ports remain open. Port management is done by the administrator itself.

Stateful Packet Filters

This type of firewall is the oldest and the most familiar type of firewall that can be programmed to a small local area network. It offers a controlled form of firewall with the administrator authorizing access individually to different connections.

Next Generation Firewalls

This is a more evolved version of firewall than standard packet filters and stateful inspection firewalls. This version of firewall has multiple layers that are able to inspect not just on the packet header level but the source and packet contents as well.

This version is also able to block more advanced forms of malware that could slip by other firewalls.

Proxy Service Firewalls

This firewall is also called a gateway firewall. The term gateway itself illustrates the function of this firewall, which acts as a sentry between incoming data from a source (internet) and the destination (your device).

This layer of firewall is more secure than packet filter and stateful inspection firewalls, because it shields the user against threats from the internet.

Stateful Inspection Firewall

A stateful inspection firewall is a multi-layered firewall that monitors the flow of network traffic. At its core, this firewall filters data streams based on parameters set by the administrator; on its own, it’s not able to distinguish safe network traffic from the malicious kind.

This type of firewall on its own does not provide enough security, but coupled with other forms of firewall, it can give a detailed insight on network traffic.

Why Do We Need Firewalls?

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In this new era of technology, it’s necessary to protect our privacy and data since we rely on our electronic devices for so much.

Use of numerous algorithms have enabled corporations to track our digital footprints. Along with that, hackers can easily invade and steal confidential data from the users. Let’s look deeper into why we need firewalls.

Preventing Loss of Data

To prevent and mediate this invasion of privacy and avoid hacking over networks that are connected to each other over the internet, a firewall is applied to act as the first line of defense. It acts as a gatekeeper and as a checkpoint. Without this protection, any network is open to threats.

By using a firewall, users can not only prevent data from being compromised, but network traffic can also be monitored and controlled by setting parameters that adapt to a situation accordingly. 

Implementation of a firewall can help reduce risk for a business network and protect sensitive information from being compromised by a cyber-attack. When establishing a business network where online transactions are done, it is highly advised to have multiple layers of firewalls. 

A cyber attack can leave a corporation completely crippled. Loss of information not only results in loss of funds but it also means potential lawsuits by the clients and shareholders.

A Safer Gaming Experience

Over time, our gaming experience has evolved on every platform. New age games now keep sensitive information on their users such as residential addresses or other personal information.

These games also may include micro-transactions that make use of credit/debit card information. All this data left unprotected can lead to identity fraud and potential theft.

Moreover, hackers can use malware to gain access to an entire system, giving the hacker complete access to the data. It lets them manipulate the data for their personal gain. The a firewall could easily prevent any such occurrences.

Restricting Access to Particular Content

Firewalls not only protect against hackers and data loss, but they can also be used to act as a parental control for younger users. A firewall can be used to block access to particular web content such as adult websites and online betting websites.


Can Firewalls Be Hacked?

Yes, firewalls can be hacked. Cybercriminals can gain access to your firewall and access your system; however, this can be prevented by having multiple layers of firewall.

Do Firewalls Prevent Viruses?

Yes, firewalls have the capability to prevent viruses from entering your system by restricting their access. However, a poorly set-up firewall can leave backdoors for viruses to enter the system.

What Is the Difference Between Hardware and Software Firewalls?

Hardware firewalls are physical devices such as routers or a hub that act as a center for network traffic exchange. This firewall can be wired or wireless.

A software firewall is essentially a software that is tailored to protect a system against threats coming in from the internet or an external network source. 

Summing It Up

A firewall is that one soldier in an army that is needed to fend off attempts of data and privacy theft. On its own, it provides very minimal but necessary security. Nonetheless, there are always backdoors that can lead to data being compromised by malware and hackers.

These setbacks can also be prevented by updating firewalls to the latest firmware available and coupling them with available anti-virus software, which can also provide the needed protection.